This study is a proposed continuation of a two year research program on the quantitation of lymph pooling in lymphedema by dual beam absorptiometry. Lymphedema is a severe, ubiquitous, and continuing affliction involving accumulation of excess lymph fluid in the extremities. Frequently its victims are cancer patients (and post-mastectomy subjects). Compressive therapy during hospitalization is the treatment of choice and is usually palliative. However, no quantitative data has been available on rate of recovery during treatment or on pre-treatment severity. Such information is needed to tailor treatment amongst these victims, in which response to treatment can be highly variable. Our original study proposed to research and evaluate (quantitate) lymph pooling in a number of subjects by means of dual beam absorptiometry. We have recently completed the first phase of this study and have obtained some significant results. We have indication that the most efficacious period of treatment is the first week; we have quantified rate of lymph pool loss, and identified possible areas for improvement of treatment, inasmuch as in some cases the standard therapy seems to be insufficient. In addition we have identified certain areas which need further investigation. These include (1) a possible "rebound" effect just prior to completion of therapy and (2) an unexplained loss of lipid in some patients. We have, also, introduced bioelectrical impedance as a second tool for investigation, to parallel and supplement absorptiometry and have obtained some promising preliminary results with this method. We propose that a continuation of this research would confirm and verify our conclusions and would also allow needed investigation of the rebound, segmental, and lipid effects. Additionally, we propose to use bioelectrical impedance measurements to extend and verify our absorptiometry results, and to test this new methodology as a clinical tool. The completion of a final phase for the project will: a) establish, for the physician, the relationship between treatment mode and response, b) prove the routine use of absorption and impedance assay systems, c) clarify the influence of such quantities as; 'rebound,' 'lipid mobilization,' 'limb segmental response,' for the clinician and suggest treatment mode adjustments for the specialist treating lymphedema. The basic disciplines are; lymphology, oncology, bioelectrical impedance, radiation physics, the specialties of compressive limb treatment and cancer patient care.